Inflammatory Markers and Immune Response to Pneumococcal Vaccination in HIV-Positive and -Negative Adults

Endogenous soluble receptors sBCMA and sTACI: biomarker, immunoregulator and hurdle for therapy in multiple myeloma

BAFF and APRIL regulate B cell homeostasis by binding to their three receptors BAFFR, BCMA and TACI. The complexity of this system is further increased by shedding of these three receptors; this reduces signaling due to the display of less surface receptors. Further, soluble forms, sBCMA and sTACI, were detected in body fluids and serve as biomarker in malignancies, autoimmune diseases and immunodeficiencies. sBCMA and sTACI function as decoys blocking BAFF and APRIL. BCMA is a promising therapeutic target in multiple myeloma, but sBCMA may reduce therapeutic activity of CAR T cells, bispecific antibodies, and antibody-drug conjugates. Insights into the biochemical mechanism of shedding of BCMA can be harnessed to improve BCMA-directed therapy by blocking its shedding with a γ-secretase inhibitor.

Race-related differences in functional antibody response to pneumococcal vaccination in HIV-infected individuals

BACKGROUND

Both HIV positivity and African American (AA) ethnicity are associated with increased incidence of invasive pneumococcal disease (IPD). Poor immune response to pneumococcal polysaccharide-based vaccines may contribute to the race related increased frequency of IPD in African American HIV positive individuals.

METHODS

Caucasian and AA HIV-infected (HIV+) individuals 40-65 years old with CD4+ T cells/µl (CD4) >200 on antiretroviral therapy (ART) received either the 13-valent pneumococcal conjugate vaccine (PCV) followed by the 23-valent pneumococcal polysaccharide vaccine (PPV) or PPV only. Serum IgG, IgM and opsonophagocytic antibody responses to serotypes 14 and 23F as well as serum IgG and opsonophagocytic antibody responses to serotype 19A were measured pre- and post-vaccination. We measured serum markers of inflammation in all participants and performed single cell gene expression profiling at the baseline by HD Biomark in Caucasians and African Americans.

RESULTS

There were no significant differences in pre-immunization inflammatory markers or post-vaccination IgG and IgM concentrations between Caucasian and African American participants. However, we found significantly lower opsonophagocytic activity in response to serotypes 14 and 19A in the AA group compared to the Caucasian group. There was no association between inflammatory markers and immune response to vaccination, however we found extensive biomodal variation in gene expression levels in single IgM+ memory B cells. Differentially expressed genes may be related to differences in the immune response between ethnic groups.

CONCLUSIONS

Distinct racial differences were found in the functional immune response following either PPV and/or PCV/PPV immunization in HIV-positive adults, although these differences were serotype dependent. Decreased ability to respond to vaccination may in part explain racial disparities in pneumococcal disease epidemiology. ClinicalTrials.gov ID: NCT03039491.

23-valent pneumococcal polysaccharide vaccine elicits hierarchical antibody and cellular responses in healthy and tuberculosis-cured elderly, and HIV-1-infected subjects

The PPV23 immunizes healthy elderly and other high-risk populations against pneumococcal disease. Immune mechanisms whereby these populations differently mount antibody(Ab) and cellular responses to PPV23 vaccination remain unknown. Here, healthy elderly, those elderly with prior tuberculosis-cured history (TB-cured), and HIV-infected humans were vaccinated with PPV23, and assessed for opsonophagocytic Ab responses and potential cellular mechanisms. PPV23 vaccination elicited hierarchical responses of opsonophagocytic Ab. PPV23-elicited Ab titers were highest in healthy elderly, significantly lower in TB-cured elderly and lowest in HIV-infected subjects. Mechanistically, high PPV23-elicited Ab titers in healthy elderly were associated with increases in CD19 + CD69+ cells and CD19 + CD138 + plasma cells. Surprisingly, TB-cured elderly failed to show PPV23-induced increases in these cells. While HIV-infected subjects showed a depressed CD19 + CD69+ cellular response, PPV23 vaccination uncovered HIV-related over-reactive increases in CD19 + CD138 + cells. For the first time, we demonstrate that PPV23-elicted opsonophagocytic Ab titers correlate with different cellular responses in healthy, TB-cured and HIV statuses.

Effectiveness and practical uses of 23-valent pneumococcal polysaccharide vaccine in healthy and special populations

Streptococcus pneumonia (S. pneumoniae) is responsible for significant morbidity and mortality throughout the world. The 23-valent pneumococcal polysaccharide vaccines (PPV23) have been widely used for many years, but challenges are remaining in some respects, especially for its effectiveness among high-risk populations and older adults. This review aims to summarize recent clinical trials and studies of PPV23 vaccination among healthy people ≥ 2 years of age and those with high-risk conditions such as pregnant women, individuals with immunocompromising diseases and other chronic conditions, and provide health officials in China and other developing countries a comprehensive understanding of the current vaccination strategies for PPV23 and for the combined use of PPV23 and pneumococcal conjugate vaccines (PCVs) in adults.

The Role of BAFF System Molecules in Host Response to Pathogens

The two ligands B cell-activating factor of the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) and the three receptors BAFF receptor (BAFF-R), transmembrane activator and calcium-modulating cyclophilin ligand interactor (TACI), and B cell maturation antigen (BCMA) are members of the "BAFF system molecules." BAFF system molecules are primarily involved in B cell homeostasis. The relevance of BAFF system molecules in host responses to microbial assaults has been investigated in clinical studies and in mice deficient for each of these molecules. Many microbial products modulate the expression of these molecules. Data from clinical studies suggest a correlation between increased expression levels of BAFF system molecules and elevated B cell responses. Depending on the pathogen, heightened B cell responses may strengthen the host response or promote susceptibility. Whereas pathogen-mediated increases in the expression levels of the ligands and/or the receptors appear to promote microbial clearance, certain pathogens have evolved to ablate B cell responses by suppressing the expression of TACI and/or BAFF-R on B cells. Other than its well-established role in B cell responses, the TACI-mediated activation of macrophages is also implicated in resistance to intracellular pathogens. An improved understanding of the role that BAFF system molecules play in infection may assist in devising novel strategies for vaccine development.

Early post-operative acute phase response in patients with early graft dysfunction is predictive of 6-month and 12-month mortality in liver transplant recipients

Early allograft dysfunction (EAD) after liver transplantation is mostly a reversible event caused by factors related to ischemia/reperfusion (I/R) injury. EAD represents a hepatic injury associated with pre- and early post-transplant inflammatory cytokine responses. Aim of the present study was to evaluate the prognostic and diagnostic value of CRP in liver transplant recipients with EAD.

MATERIALS AND METHODS

Forty-seven patients with EAD were compared with 115 non-EAD patients. Pre- and post-transplant parameters were analyzed. EAD was defined based on postoperative liver function tests such as INR, bilirubin and liver enzymes. Statistical analysis was performed using SPSS version 18.0.

RESULTS

Pre-transplant liver enzyme were not significantly different in the two groups. At day 3, 5 and 10 post-transplant CRP was significantly higher in patients with EAD than in non-EAD patients (p⩽0.001 for all investigations) and remained consistently high in patients with EAD and low in non-EAD patients. EAD patients with high CRP at post-transplant days 3 and 5 showed lower survival at 6-month and 12-month post-transplant than patients with low CRP.

CONCLUSION

Our results indicate a prognostic and diagnostic value of CRP in patients with early graft dysfunction and predict 6-month and 12-month mortality in liver transplant recipients.